Magnetically heated granular gas in a low-gravity environment

Magnetic forces are used to heat up thousands of spherical particles under low-gravity. This long range external excitation, combined with the induced particle-particle interactions, results in a homogeneous spatial distribution of the particles. Comparisons with predictions of kinetic theories can hence be carried out. Haff's cooling law is verified qualitatively, while the measured cooling time scale is quantitatively different from the prediction. The high velocity tail of the velocity distribution during homogeneous cooling state (HCS) is measured, while the expected cluster formation after HCS can not be verified by our experiment.